From: Andrew Morton <akpm@linux-foundation.org>
To: Miaohe Lin <linmiaohe@huawei.com>
Cc: <sjenning@redhat.com>, <ddstreet@ieee.org>,
<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>
Subject: Re: [PATCH 1/2] mm/zbud: reuse unbuddied[0] as buddied in zbud_pool
Date: Mon, 7 Jun 2021 16:10:10 -0700 [thread overview]
Message-ID: <20210607161010.94168ddc8128da6af1e45cea@linux-foundation.org> (raw)
In-Reply-To: <20210605075141.1359969-2-linmiaohe@huawei.com>
On Sat, 5 Jun 2021 15:51:40 +0800 Miaohe Lin <linmiaohe@huawei.com> wrote:
> Since commit 9d8c5b5284e4 ("mm: zbud: fix condition check on allocation
> size"), zbud_pool.unbuddied[0] is always unused. We can reuse it as buddied
> field to save some possible memory.
>
> ...
>
> --- a/mm/zbud.c
> +++ b/mm/zbud.c
> @@ -96,7 +96,7 @@
> struct zbud_pool {
> spinlock_t lock;
> struct list_head unbuddied[NCHUNKS];
> - struct list_head buddied;
> +#define buddied unbuddied[0]
> struct list_head lru;
> u64 pages_nr;
> const struct zbud_ops *ops;
That looks a bit hacky. Can we at least have a comment explaining
what's going on?
Would it be better to implement this with a union, rather than a #define?
next prev parent reply other threads:[~2021-06-07 23:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-05 7:51 [PATCH 0/2] Cleanups for zbud Miaohe Lin
2021-06-05 7:51 ` [PATCH 1/2] mm/zbud: reuse unbuddied[0] as buddied in zbud_pool Miaohe Lin
2021-06-07 23:10 ` Andrew Morton [this message]
2021-06-08 1:41 ` Miaohe Lin
2021-06-05 7:51 ` [PATCH 2/2] mm/zbud: don't export any zbud API Miaohe Lin
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